Pneumatic hammer.



R. BURNS & C.. K. P|CKLES. PNEUMATIG HAMMER.

(Applieaion med .my 1u 1899.) (No Model.)

Patented Oct. 24, |899.

NTTnn STATES Frio.

ROBERT BURNS, OF CHICAGO, ILLINOISQAND CHARLES K. PICKLES, OF ST.

SAID PICKLES ASSIGNOR TO BURT E. TILDEN, OF

PNEUMATIC HAIVHVI ER.

SPECIFICATION forming part of Letters Patent No. 635,422, dated October 24, 1899.

Application filed July l5, 1899. Serial No. 723,999. (No model.)

To ctZZ whom, it" may concern,.-

Beit known that we, ROBERT BURNS, of Chicago, in the county of Cook and State of Illinois, and CHARLES K. PIOKLES, of St. Louis, in the State of Missouri, citizens of the United States, have invented certain new and useful Improvements in Pneumatic Hammers; and we do hereby declare the following to be a full, clear, and exact description of the same, reference being had to the accompanying drawings, forming a part of this specification.

The present invention relates to that type of pneumatic engines in which the reciproeating piston constitutes a hammer adapted to deliver a series of rapidly-recurring blows to .a chipping or other tool, the shank of which is located in the path of such impactpiston and constitutes an end closure for the lower piston-chamber.

The objects of the present improvement are, first, to provide a simple and efficient sectional formation and arrangement of the main cylinder for the impact-piston and the Valve-block and housing for the reversingvalve, which permits of a ready and convenient detachment of the parts for cleaning, repair, and replacement of worn parts; second, to provide means for connecting the handle, main cylinder, and valve-block'and housing together in a rigid and substantial manner; third, to provide means self-contained within the hammer for the automatic lubrication of the hammer parts while in operation. We attain such objects by the construction and arrangement of parts illustrated in the accompanying drawings, in which- Figure lis a longitudinal sectional elevation at line com, Fig. 3, illustrating the position of the parts at the commencement of the forward stroke of the impact-piston of the present pneumatic hammer; Fig. 2, a fragmentary longitudinal section at line 0c', Fig. 3, illustrating the position of the parts at the ending of such forward stroke of the impactpiston and with the valve reversed to effect a backward or return movement of such piston; Fig. 3, a horizontal section at line'x2 002, Figs.l 1 and 2; Fig. 4, a side elevation of the 'valve-block in aA detached condition; Fig. 5, 5o

a side elevation of the reversing-valve in a detached condition.

Similar numerals of reference indicate like parts in the several views.

Referring to the drawings, 1 represents the 55 main cylinder or casing, the lower end of which is provided with a guide-bushing 2, thatV receives the shank portion of the chipping or other tool, as usual in the present type of hammers.

y3 is the cylindrical impact-piston, .adapted to have reciprocating movement in the bore ofthe main cylinder 1 and formed with an annular recess or chamber 4 near its upper end. Such piston is also provided with reduced'aXially-arranged end extensions 5 and 6, the lower extension 5. constituting the impact portion of the piston to impact upon the shank of the chipping orother tool employed, while the upper extension G is adapted to en- 7o ter a central chamber in the valve-block of the hammer to effect a cushioning action upon the piston as it nears the end of its upward or return stroke. Such piston is also formed with a port or passage 7, connecting the annular passage or chamber 4 of the piston with the lower piston-chamber, .as illustrated in Fig. 2.

8 is the circularly-enlarged base of the valve-block of the present invention, which 8o constitutes a head for closing the upper end of the main cylinder 1, and offset to fit the same, as illustrated in Figs. 1 and 2.

9 is an axially-arranged hollow cylindrical portion of the valve-block, closed at its upper end and open at its lower end to form an axially-arranged chamber adapted to receive the upper cylindrical extension 6 of the impact-piston, as heretoforedescribed. A

10 is the cylindrical valve housing, ar- 9o ranged concentrically to the cylindrical portion 9 of the valve-block and offset or counterbored to form, in connection with such valve-block, upper and lower valve-chambers 11 and 12 of differential areas, the upper one 95 of said chambers having an area smaller than the lower one, as shown. Said Yvalve-housing 10 is preferably of an external diameter equal to that of the main cylinder 1 and fits against the offset upper end of the enlarged base S of the valve-block, as shown.

13 is the reversing-val ve of an annular form with an internal diameter equal to the external diameter of the cylindrical portion fl of the valve-block and adapted to have its seat thereon.

The lower portion of the valve 13 is formed by an enlarged head 1l, that has movement in the lowerenlarged valve-chamber 12, while the upper and main portion of the valve is of a lesser diameter and is adapted to have movement in the correspondingly-reduced upper valve-chamber 11. As so constructed the reversing-valve is ot' a diiierential nature, having ditlerential pressure areas on its opposite faces and adapted to operate under differential effects of fluid-pressure, as usual in the present type of reversing-valve, and the arrangementis such that the motive fluid will exert constant pressure upon the upper and smaller area of the valve.

15 is an annular internal exhaust-chamber in the main portion of the reversing-valve 13, and 1G are openings through the wall of such chamber, the chamber and openings being adapted to contrl communication between the upper and lower piston-chambers of the main cylinder and the exhaust-port 17 in the valve-housing 10, that opens to the atmosphere, as shown in Figs. 1, 2, and 3.

18 is a longitudinal port or passage formed in the main cylinder 1, the valve-block head 8, and valve-housing 10, the upper end ot' which has connection with the lower end of the enlarged lower valve-chamber 12, while its extreme lowerend opens into the interior of the main cylinder 1 at a point that will permit of an exhaust of the motive fluid from the lower valve-chamber 12 when the impactpiston 3 is in its upper position, as illustrated in Fig. 1.

2O is a longitudinal port or passage formed like the port or passage 13 in the main cylinder 1, the valve-block head S, and the valvehousing 10, with its upper end communicating with the pressure-supply chamber at the upper end of the hammer, while its lower end communicates with the interior of the main cylinder 1 at a point opposite the small lateral branch 19 of the longitudinal passage 18, heretofore described, the arrangement being such that as the annular peripheral chamber lof the impact-piston uncovers said passages to put the saineinto communication the fluidpressure will be introduced into the lower valve-chamber12 to force the reversing-valve 13 into its upper position, as indicated in Fig. 2. At the same time a restricted supply of motive fluid is admitted into the lower piston-chamber through the port or passage 7 to effect au upward or return movement of theA impact-piston 3.

2l are one or more ports or passages through the upper end of the cylindrical portion 9 of the valve-block and in the path of the upper end of the reversing-valve 13 and through which motive fluid is admitted to the upper piston-chamber in a controllable manner.

22 is a relief or exhaust port or passage form ed in the main cylinder 1, the valve-block base S, and valve-housing 10 and connecting the lower piston-chamber with the atmosphere in a controllable manner, its lower end communicating with the lower end of the lower piston-chamber, while its upper end opens into the reversing-valve chamber at a point adjacent to the exhaust-chamber 15 of the main reversing-valve, so that with the parts in the position illustrated in Fig. 1 the port or passage 22 will be in communication with the atmosphere through the exhaustchamber 15 and openings 16 of the reversingvalve, and with the parts in the position illustrated in Fig. 2 the exhaust nature of the passage 22 will be rendered inactive by the lower enlarged head 1-1- of the reversing-valveV closing communication between said passage and the exhaust-chamber of the valve.

23 is the attaching sleeve or hub of the hammer-handle, fitting over the valve-lionsing l0, the valve-block base S, and the circular flange 2-1 on the upper end of the main cylinder 1, the bore ot' such hub or sleeve being formed with annular offsets to engage the upper marginal edges ot the valve-housing 1f) and the valve-block base S and hold the same in proper relative position.

The extreme lower end of the sleeve orhub 23 is internally screw-threaded to receive the annular nut 25, that has engagement against the under side of the flange 24 of the main cylinder, as shown in Figs. 1 and 2, the construction being such that said nut is adapted to forcibly clamp and hold the main cylinder, valve-bloek,ai1d valve-housingin proper relative position.

2G is a transverse locking-bolt passing through ears 27,that are located on either side of a vertical slit 28 in the lower end of the sleeve or hub 22 of the hammer-handle, the construction being such as to afford a substantial means for contracting the lower end of said sleeve upon the annular nut 25 after an adjustment has been attained and prevent a jarring loose of the parts in use.

29 is the supply-passage for the motive fluid, formed in one of the branches 30 of the hammer-handle and communicating at its lower end with the main supply-chamber 31 at the upper end of the hammer, while its upper end is interseeted by the casing 32 of the manually-actuated controlling-Valve 33.

In the construction illustrated in Fig. 1 the valve is of the reciprocating-piston type, formed with an annular peripheral passage or chamber 34, adapted to register with oppositely-arranged orifices 35 in the stationary valve-casing 32 and by its movement to control the supply of motive fluid to the hammer mechanism.

36 is a spring tending to hold the valve 33 in its closed condition.

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37 is a pivoted trigger or thumb-lever having engagement with one end of the valve and adapted to impart an opening movement to the same.

In the present invention the shank portion of the valve 33 is of an enlarged formation that is chambered out to constitute an oil chamber or reservoir 38, the filling-opening of which extends outthrough the forward end of the valve and is closed by a screw-threaded bolt or stopper 39, as shown in Fig. l, so as to afford a convenient means for filling the oil-reservoir.

40 is the oil-feeding orifice from the reservoir, located inthe sunken wall of the annular passage 34 of the valve, which orifice is controlled byaneedle-valve 4l, also arranged in such cavity or passage 34. With the described construction the oil will feed from the orifice 40 into the annular passage 34, directly in the path of the incoming motive fluid, so as to be carried by the same directly to the various moving parts of the hammer to effect a very perfect and efficient lubrication of the same.

The operation of the present hammer mechanism is as follows: Starting with the parts in the position illustrated in Fig. 1, the motive fluid from the main supply-chamber 31 passes through the ports 2l into the valveblock chamber to press upon the upper end extension 6 of the impact-piston 3 and acting against the decreased area thereof imparts a light initial movement to the piston, which from practical experience is found to be very efficient in reducing the amount of jar or vibration that is usual in the present type of hammers. With the end extension 6 of the impact-piston forced out of the chamber of the valve-block the full area of the piston is exposed to the motive fluid and an active and forcible downward movement of the piston takes place. In such downward movement of the piston the pressure of the motive fluid continues until the annular chamber 4 of the piston registers the port or passage 2O with the opening 19 of the port or passage 18, after which the remainder of the active stroke of the piston is dependent upon its momentum. WithA the port or passage 20 and opening 19 in communication by means of the annular passage 4 of the piston the motiveiuid pressure is admitted to the lower enlarged valve chamber 12, against the enlarged head 14 of the reversing-valve, to force said valve into its upper position, as indicated in Fig. 2, to cut off the supply of motive fluid to the upper piston-chamber through p orts 21 and bymeans of its exhaust-chamber 15 and openings 16 establish communication between the upper piston-chamber and the eX- haust-port 17 to the atmosphere. At the same time motive fluid passes down through the restricted port or passage 7 in the piston into the lower piston-chamber to cause a comparatively slow return or upward movement ofthe piston. With the return of the piston to its upper position the lower end of the port or passage 18 is uncovered and communication between the same and the lower pistonchamber is established, as illustrated in Fig. 1, which allows the pressure in the lower valve-chamber 12 to exhaust therefrom and permit the constant Huid-pressure upon the upper and reduced end of the valve to again force the same into its lower position to recommence a fresh cycle of the operations just described.

Having thus fully described our said invention, what we claim as new, and desire to secure by Letters Patent, is

1. In a pneumatic hammer,the combination of a piston, a piston-cylinder, a valve-block closing the end of such cylinder and provided with a hollow cylindrical extension forming a valve-seat, a valve-housing, and a Huid-actuated valve surrounding said valve-seat and having differential pressure areas, the reduced pressure area of the valve being under constant motive-fluid pressure, and the larger pressure area of the valve under an intermittent motive-iiuid pressure, substantially as set forth.

2. In a pneu matic hammer,the combination of a piston, a piston-cylinder, a valve-block closing the end of such cylinder and provided with a hollow cylindrical extension forming a valve-seat, a valve-housin g, a fluid-actuated valve surrounding said valve-seat and having differential pressure areas, the reduced pressure area of the Valve being under constant motivefluid pressure, and a passage controlled by the piston for intermittently adv mitting the lnotive iiuid to thelarger pressure area of the valve, substantially as vset forth.

3. In a pneumatic ham mer,the combination of a piston, a piston-cylinder, a valve-block closing the end of such cylinder and provided with a hollow cylindrical extension forming a valve-seat, a valve-housing, a duid-actuated valve surrounding said valve-seat,and having differential pressure areas, the reduced pressure area of the valve being under constant motive-fluid pressure, a passage controlled by the piston and opened by the latter on its downstroke to admit motive fluid to the larger area of the valve, and an exhaust-passage leading from said larger area of the valve and opened by the piston in its upward stroke, substantially'as set forth.

4. In a pneu matic hammer,the combination of a piston, a piston-cylinder, a valve-block closing the end of such cylinder and provided with a hollow cylindrical extension forming avalve-seat, a valve-housing, a fluid-actuated valve surrounding said valve-seat,and having differential pressure areas, the reduced pressure area of the-valve being under constant motive-Huid pressure, and the larger pressure area of the valve under an intermittent motive-fluid pressure, and a longitudinal passage connecting the lower piston-chamber with the exhaust-chamber of the valve, substantially as set forth.

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5. In a pneumatic ham mer,the combination of a piston, a piston-cylinder, a valve-block closing the end of such cylinder and provided with a hollow cylindrical extension forming a valve-seat, a valve-housing, a Huid-actuated valve surrounding said valve-scat and having differential pressure areas, the reduced pressure area of the valve being under constant motive-fiuid pressure, and the lower pressure area of the Valve under an intermittent motive-fluid pressure, a longitudinal passage in the cylinder and a passage through the piston, and an annular peripheral chamberin the piston adapted to admit motive-fluid pressure to the lower piston-chamber, substantially as set forth.

6. In a pneu matic ham mer,the combination of a piston, a piston-cylinder, a valve-block closing the end of such cylinder and provided with a hollow cylindrical extension forming a valve-seat, a valve-housing, a duid-actuated valve surroundin g said valve-seat, and having differential pressure areas, the reduced pressu'e area of the valve being under constant motive-Huid pressure,and passages controlled by the piston, and adapted to introduce motive-iluid pressure into the enlarged valvechamber to hold the valve in its upper position, substantially as set forth.

7. In a pneumatic hammer,the combination of a piston formed with a reduced cylindrical extension on its upper end, a piston-cylinder, a valve-block closing the upper end of the cylinder and provided with a hollow cylindrical extension forming a valve-seat, and a chamber to receive the extension on the upper end of the piston, ports connecting the upper end of such chamber with the Inotive-fiuid-supply chamber, and a valve controlling said ports, substantially as set forth.

8. In apneumatic hammer,the combination of a piston, a piston-cylinder provided with a flanged upper end, a valve-block closing the end or" such cylinder, a valve-housing fitting the valve-block, a handle-attaching sleeve or hub fitting over the respective parts and formed with offsets to engage the valve-housing and valve-block, the lower end of such hub being internally screw-threaded, and an annular nut screwing into such lower end of the hub and abutting against the flange of the main cylinder to clamp the various parts together, substantially as set forth.

9. In a pneumatic hammer,the combination of a piston, a piston-cylinder provided with a flanged upper end, a valve-block closing the end of such cylinder, a valve-housing fitting the valve-block, a handle-attaching sleeve or hub fitting over the respective parts and formed with offsets to engage the valve-housing and valve-block, the lower end of such hub being internally screw threaded and formed with' a vertical slit, lugs at the adjacent side of said slit, a clamping-bolt pass- 4 the motive fiuid, the shank of which is formed l with an oil chamber' or reservoir, the fillingneck of which extends through one end of the valve, and a stopper' closing said filling-neck, the said reservoir having an outlet adapted to deliver the oil in the path of the motive fluid, substantially as set forth.

In testimony whereof witness our hands this 3d day of July, 1899.

ROBERT BURNS. CHARLES K. PICKLES. Witnesses:

JAMES LAvALLIN, Josrn V. PioKLEs. 

